Blood from Stones: It's Actually A Thing

Rain falling over desert, credit: Jessie Eastland/Wikimedia

I love taxonomy. (Is that the dullest statement to ever open a blog post?) I love taxonomy so very much. I love the intricate details of identification, relationships and classification, and the names, oh the names. Taxonomy is a Language of Magic.

Taxonomy usually refers to the classification of living organisms, Linnean-style, Kingdom-Phylum-Class-Order-Family-Genus-Species, but equally taxonomic to me is lexicography, the classification of words, and I know etymology isn't quite the same thing and yet it feels like also a kind of taxonomy, with those beautiful trees of descent, Greek-Latin-Late Latin-Old French-Middle English-Late Middle English.

Fly leg, credit: LoKiLeCh/Wikimedia

Taxonomists of creatures learn to count hairs on the legs of flies and measure the gill rakers of fish; taxonomists of words learn to spot new usage on highway signs and recognize Indo-European roots buried under centuries of creative spelling.

By profession I am neither kind of taxonomist, though I confess to lifelong armchair proclivities in both directions. Yesterday, I experienced a sublime moment of amateur etymological joy.

Several chapters into the book How to Read Water, I encountered the word petrichor. I've seen it a few times before, and marveled at it each time, like a shiny new insect. But despite my infatuation with it, the word resisted lodging in my mind. Whenever I stepped outside after a long-awaited rain and filled my nose with that distinctive scent, my mouth remained empty of the word that so precisely describes that scent.

This time I was determined to net the shiny creature and pin it in my collection. "Petrichor, petrichor," I mused aloud, wondering if I could make a mnemonic. "Pet Trick Core?" Nope. I looked at the page more closely. Petrichor. My brain itched. There's a word in there, a word I know: ichor, blood. Take it out, and what's left? I all but smacked my forehead and cried d'oh. Petr, rock. How had I missed it?

blood from a stone, credit: katiew/flickr

Petrichor. Rock blood. It's a real thing. Over time the dry earth becomes infused with chemicals from plants and bacteria, and when rain falls it aerosolizes the compounds, sending aromas to our noses.

Reading up on it now, I learn that "petrichor" was coined in 1964, which is recent by at least some linguistic standards (it's got nothing on "d'oh"). For more, see Wikipedia and the (unfortunately paywalled) Nature article in which two Australian scientists first presented the coinage.

It's a delight to learn the word's background, of course, but still for me a lesser delight than puzzling apart the word for myself.

For more about the wonder of taxonomy (creatures), I highly recommend the ebullient, rigorous Echinoblog.
For more about the wonder of taxonomy (words), I recommend with similar fervor the book Word by Word.
And for more about petrichor itself: The smell of rain: how CSIRO invented a new word.